I know the answer to that one; questions that are hard to answer
concerned things that were not very important when we were evolving
the ability to answer questions.
The Savanna Principle: Why Our Brains Are Stuck in the Stone Age
...there is nothing special about the human brain as a body part-leads
to an important implication. Just as the basic shape and functions of
the hand or the pancreas have not changed since the end of the
Pleistocene Epoch ("the Ice Age") about ten thousand years ago, the
basic functioning of the brain has not changed very much in the last
ten thousand years. The human body (including the brain) evolved over
millions of years in the African savanna and elsewhere on earth where
humans lived during most of this time. This ancestral environment,
where humans lived in small bands of 150 or so related individuals as
hunter-gatherers, is called the environment of evolutionary
adaptedness, or the ancestral environment. It is to the ancestral
environment that our body (including the brain) is adapted. Even
though we live in the twenty-first century, we have a Stone Age brain
(just like we have Stone Age hands and a Stone Age pancreas).
The evolved psychological mechanism produces adaptive behavior in the
ancestral environment. Adaptive behavior is behavior that increases
the chances of survival or reproductive success by solving the
adaptive problems. Eating lots of sweet and fatty foods, which contain
higher calories, is adaptive behavior that solves the adaptive problem
of procuring sufficient food to survive. Becoming jealous at the
remotest possibility of a mate's sexual infidelity, and guarding that
mate so that she could not have sexual contact with other men, is
adaptive behavior that solves men's adaptive problem of paternity
uncertainty.
Our hominid ancestors spent 99.9 percent of their evolutionary history
as hunter-gatherers on the African savanna and elsewhere on earth. It
was not until about ten thousand years ago, when the Agricultural
Revolution happened, that our ancestors started planting and
cultivating their food through agriculture and animal husbandry.
Almost everything we see around us today-cities, nation-states,
houses, roads, governments, writing, contraception, TVs, telephones,
and computers-came about in the last ten thousand years. Recall that
our entire body is adapted to the ancestral environment and that we
have a Stone Age body (including the brain). That means that our body
is not necessarily adapted for things that came about since the end of
the Pleistocene Epoch about ten thousand years ago. Ten thousand years
is a very short period of time on the evolutionary time scale; it is
simply not enough time for our body to make changes to accommodate
things that came about in the meantime, especially since the
environment has been changing too rapidly relative to how slowly we
mature and reproduce. (It takes humans about twenty years to mature
and be ready to reproduce. And, remember, only twenty years ago, for
most people outside of the military and scientific circles, there was
no such thing as the Internet or cell phones.) In other words, we
still have the same evolved psychological mechanisms that our
ancestors possessed more than ten thousand years ago.
This observation leads to a new proposition in evolutionary psychology
called the Savanna Principle, which states that the human brain has
difficulty comprehending and dealing with entities and situations that
did not exist in the ancestral environment.
One example of an entity that did not exist in the ancestral
environment is TV or any other realistic images of other humans, such
as photographs, videos, or films. The Savanna Principle would
therefore predict that the human brain has difficulty comprehending
and dealing with images shown on TV. This indeed appears to be the
case.28 A recent study shows that individuals who watch certain types
of TV programs are more satisfied with their friendships, as if they
had more friends or socialized with them more frequently. According to
the Savanna Principle, this is probably because the human brain,
adapted to the ancestral environment, has difficulty distinguishing
between our real friends in the flesh and the characters we repeatedly
see on TV. In the ancestral environment, any realistic images of other
humans were other humans, and if you saw them repeatedly and they did
not try to kill or harm you in any way, then more than likely they
were your friends. Our Stone Age brain therefore assumes that the
characters we repeatedly encounter on TV, very few of whom try to kill
or harm us, are our real friends, and our satisfaction with
friendships thereby increases by seeing them more frequently.
Maladaptive Adaptations
Take the example of our preference for sweets and fats as an evolved
psychological mechanism. This psychological mechanism solved the
adaptive problem of survival in the ancestral environment by allowing
those who possessed it to live longer. Our preferred consumption of
sweets and fats was therefore adaptive in the ancestral environment.
However, we now live in an environment where sweets and fats are
abundantly available in every checkout line in every supermarket, in
every city, in every industrial society, twenty-four hours a day,
seven days a week. In other words, the original adaptive problem
(malnutrition) no longer exists; very few people die of malnutrition
in industrial societies. Yet we still possess the same psychological
mechanism that compels us to consume sweets and fats. Because our
environment is so vastly different from the ancestral environment, we
now face a curious situation where those who behave according to the
dictates of the evolved psychological mechanism are worse offin terms
of survival. Obesity (to which overcon-sumption of sweets and fats
leads) hinders survival. The Savanna Principle suggests that we
continue to have (currently maladaptive) preferences for sweets and
fats, and as a result become obese, because our brain cannot readily
comprehend the supermarkets, the abundance of food in general, and
indeed agriculture, none of which existed in the ancestral
environment. Our brain still assumes we are hunter-gatherers with very
precarious and unpredictable sources of food. If our brain truly
comprehended supermarkets, we would not crave sweet and fatty foods.
Similarly, male sexual jealousy is another evolved psychological
mechanism that hasn't quite caught up to modern times. It solved the
adaptive problem of reproduction in the ancestral environment by
allowing men who possessed it to maximize paternity certainty and
minimize the possibility of cuckoldry. Sexual jealousy was therefore
adaptive in the ancestral environment. However, sex and reproduction
are often separated in the modern environment; many episodes of sex do
not lead to reproduction. There is an abundance of reliable methods of
birth control in industrial societies, and many women use the
contraceptive pill. For these women, sexual infidelity does not lead
to childbirth, and their mates will not have to waste their resources
on someone else's children. Even if their mates cheated on them and
got pregnant as a result, reliable paternity testing removes any
paternity uncertainty. In other words, the original adaptive-problem
(paternity uncertainty) is less of a threat to reproductive success;
men today are much less likely to invest unwittingly in someone else's
genetic children. Yet men still possess the same psychological
mechanism that makes them jealous at the possibility of their mates'
sexual infidelity and compels them to guard their mates to minimize
the possibility of cuckoldry. The fact that his adulterous wife was on
the Pill at the time of her sexual infidelity offers very little
consolation to a man.
Further, once again because our current environment is so vastly
different from the ancestral environment, we now face a curious
situation where those who behave according to the dictates of the
evolved psychological mechanism are often worse off in terms of
reproductive success. Extreme forms of mate guarding, such as violence
against mates or romantic rivals, are crimes in most industrial
nations. Incarceration, and consequent physical separation from their
mates, does everything to reduce the reproductive success of the men.
Yet men continue to exhibit sexual jealousy, and many men engage in
extreme forms of mate guarding and vigilance, including violence.29
The Savanna Principle suggests that this is because their brains
cannot truly comprehend effective birth control, written laws, the
police, and the courts. If they did, they would not engage in extreme
forms of mate guarding (such as violence) or any other criminal
behavior for which they would likely go to jail.
We caution you that the Savanna Principle as stated above was proposed
very recently (even though it is based on observations made earlier by
pioneers of evolutionary psychology)30 and is not yet part of the
established literature of evolutionary psychology. Its implications
have yet to be subjected to rigorous experimental testing. However, we
refer to it throughout the rest of the book, because we believe there
is a kernel of truth to it and that it can explain a wide range of
otherwise puzzling instances of human behavior.
Human Evolution Pretty Much Stopped about Ten Thousand Years Ago
The Savanna Principle points to a couple of very important-but often
neglected-observations about human evolution: Evolution happens very
gradually, and natural selection requires a stable, unchanging
environment to which it can respond.
Evolution takes many generations, and so the speed of evolution of a
species is relative to how long it takes for individuals of the
species to mature sexually. Evolution happens faster for fast-maturing
species and slower for slow-maturing species. Fruit flies are one of
the fastest-maturing species in nature, and humans are one of the
slowest. It takes only seven days for fruit flies to mature sexually
under ideal conditions, whereas it takes fifteen to twenty years for
humans. It means that there can be more than fifty generations of
fruit flies in one year, before a human baby can even begin to walk.
There are more than a thousand generations of fruit flies in one human
generation (twenty years), for which humans need more than twenty
thousand years. Evolution for fruit flies can happen pretty fast,
which is precisely the reason why they are the favorite species for
geneticists to study. Human evolution happens much, much more slowly.
No human scientists can see it in action the way they can observe
fruit fly evolution unfold in the lab.
The second point is even more important: Natural selection under most
circumstances requires a stable, unchanging environment for many, many
generations. For example, if the climate is very cold for centuries
and millennia, then gradually individuals who have better resistance
to cold will be favored by natural selection, and their neighbors who
have less resistance to cold (who are more adapted to hot climates)
will die out before they can leave many children. This will happen
generation after generation, until one day all humans have great
resistance to cold. A new trait-resistance to cold-has now evolved and
become part of universal human nature. But this trait could not have
evolved if the climate was cold for one century (only five human
generations, albeit 5,200 fruit fly generations) and then hot for
another century, only to be cold again in the third century. Natural
selection would not know who (with which traits) to select.
Since the advent of agriculture about ten thousand years ago and the
birth of human civilization which followed, humans have not had a
stable environment against which natural selection can operate. For
example, a mere two centuries (ten generations) ago, the United States
and the rest of the Western world were largely agrarian; most people
were farmers. In the agrarian society, men achieved higher status by
being the best farmers; those who possessed certain traits that made
them good farmers had higher status and thus greater reproductive
success than others who didn't possess such traits.
Then, only a century later, the United States and Europe were
predominantly industrial societies; most men made their living working
for factories. Traits that make men good factory workers (or, better
yet, factory owners] may or may not be the same as the traits that
make them good farmers. Certain traits-such as intelligence,
diligence, and sociability-probably remain important,31 but others-
such as a feel for nature, the soil, and animals, and the ability to
work outdoors or forecast weather-cease to be important, and other
traits-such as punctuality, the ability to follow instructions, a feel
for machinery or mechanical aptitude, and the ability to work jWoow-
suddenly become important.
Now we are in a post-industrial society, where most people work
neither as farmers nor factory workers but in the service industry.
Computers and other electronic devices become important, and an
entirely new set of traits is necessary to be successful. Bill Gates
and Sir Richard Branson (and other successful men of today) may not
have made particularly successful farmers or factory workers. All of
these dramatic changes happened within ten generations, and there is
no telling what the next century will bring and what traits will be
necessary to be successful in the twenty-second century. We live in an
unstable, ever-changing environment, and have done so for about ten
thousand years.
For hundreds of thousands of years before that, our ancestors lived as
hunter-gatherers on the African savanna, in a stable, unchanging
environment to which natural selection could respond. That is why all
humans today have traits that would have made them good hunter-
gatherers in Africa-men's great spatiovisual skills, which allowed
them to follow animals on a hunting trip for days and for miles
without a map or a global satellite positioning device and return home
safely; and women's great object location memory, which allowed them
to remember where fruit trees and bushes were and return there every
season to harvest, once again without maps or permanent landmarks.
For the last ten thousand years or so, however, our environment has
been changing too rapidly for evolution to catch up. Evolution cannot
work against moving targets. That's why humans have not evolved in any
predictable direction since about ten thousand years ago. We hasten to
add that certain features of our environment have remained the same-we
have always had to get along with other humans, and we have always had
to find and keep our mates-so certain traits, like sociability or
physical attractiveness, have always been favored by natural and
sexual selection. But other features of j our environment have changed
too rapidly relative to our generation time, in a relatively random
fashion-who could have predicted computers and the Internet a century
ago?-so we have not been able to adapt and evolve against the
constantly moving target of the environment.
Why Beautiful People Have More Daughters
From Dating, Shopping, and Praying to Going to War and Becoming a
Billionaire-Two Evolutionary Psychologists Explain Why We Do What We
Do.
by Alan S. Miller (Author), Satoshi Kanazawa
http://www.amazon.com/Beautiful-People-Have-More-Daughters/dp/0399533656
